While it will be hard to firmly diagnose the exact problem, we can give suggestions for you to try. First thing I will say is keep an open mind.
Your rifle seems to be fairly accurate, .75" with factory fodder is good. The 7600/760 series that I have shot in the past have been fairly accurate also. The barrels on these are actually free-floated.
The first thing I would try is a slower powder. While IMR 4064 is a known good .30-06 powder, it just seems too fast (to me). IMR 4350 is also a good all-around powder and shoots well in alot of different calibers. I would try a little H4831 or RL22. I especially like RL22, it shoots extremely well in my .25-06/7mmRemMag and the 7mm/300 WSM
and 300WinMags that I have reloaded for.
As for primers, I usually use CCI BR2's or Rem 9.5, 9.5M's. I've bought all the "others" before, but these "show me the money".
Some say the SST's aren't that accurate. I got good results (.451") for four shots with the 154gr in 7mmRM. You may want to give the same weight Ballistic Tips a try. They are relatively cheap considering the accuracy you can get from them. Think the .30cal/165gr is on sale at MidwayUSA right now for 9.99/50 ct.
Hope this tips help. Johnny K.